This application constitutes the fourth competitive renewal of the Mount Sinai School of Medicine Alzheimer's Disease Research Center. Its fundamental goals have not change since the first funding period, however it has expanded much since then. In this renewal the following cores and projects are propose: . Clinical Research Support Core/El hurst Satellite (D. Marin) . Information Transfer Core (R. Mohs) . Neuropathology Core (D. Perl) . Project: "Molecular Genetic Studies of Neurofilament Assembly and Function" (R. Lazzarini) . Project: "Quantitative Indices of Neuron Vulnerability in Dementia" (P. Hof) . Project: "Novel Presenilin Binding Proteins" (J. Buxbaum) . Project: "Vascular Localization and Function of Presenilin 1 Fragments (N. Robakis) . Project: "An alpha2 Agonist and Cholinesterase Inhibitor in AD" . Project: "Risk Factors in Very Late Onset AD" (J. Silverman)